Worth 30 ! will award
and btw this is not a equilateral triangle so alpha is not 50

x=20 degrees

Step-by-step explanation:

A triangle has 120 degrees in total. If you add all the givin angles then you will get 80. 120-80=40. Those 2 blank sides are the same length.  So you divide 40 by the 2 angles. 40/2=20

We can consider this triangle as inscribed in a circle,where angle at center is twice at circumference.

40+10=50

180-50=130.

angle at center is 130°

at circumference will be;

130/2=65

65-10=55°

considering the bottom most triangle;

40+20+10+65=135°

180-135=45

Answer=45°